Re: [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
From: Michal Hocko <hidden>
Date: 2012-05-28 19:13:30
Also in:
lkml
On Mon 28-05-12 20:51:30, Aneesh Kumar K.V wrote:
From: "Aneesh Kumar K.V" <redacted> The change was introduced by "hugetlb: simplify migrate_huge_page() " We should use compound page head instead of tail pages in migrate_huge_page(). Signed-off-by: Aneesh Kumar K.V <redacted> --- mm/memory-failure.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) This is an important bug fix. If we want we can fold it with the not yet merged upstream patch mentioned above in linux-next. The stack trace for the crash is [ 75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350 [ 75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0 [ 75.338386] Oops: 0002 [#1] SMP [ 75.338386] CPU 1 [ 75.338386] Modules linked in: ... ... [ 75.338386] Call Trace: [ 75.338386] [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c [ 75.338386] [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c [ 75.338386] [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421 [ 75.338386] [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31 [ 75.338386] [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55 [ 75.338386] [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c [ 75.338386] [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55 [ 75.338386] [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc [ 75.338386] [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27 [ 75.338386] [<ffffffff81100839>] try_to_unmap+0x25/0x3c [ 75.338386] [<ffffffff810641c2>] ? console_unlock+0x210/0x238 [ 75.338386] [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178
This should be part of the changelog.
quoted hunk ↗ jump to hunk
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4a45098..53a1495 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c@@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags) } /* Keep page count to indicate a given hugepage is isolated. */ - ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true); - put_page(page); + ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true); + put_page(hpage); if (ret) { pr_info("soft offline: %#lx: migration failed %d, type %lx\n", pfn, ret, page->flags);
I guess you want hpage->flags here. -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>